Simethicone is a liquid, oily composition. Simethicone comprises liquid methylsiloxane polymers containing a small amount of silica. Since approximately 1960, it has been used as an anti-gas and antiflatulent agent in pharmaceutical compositions. It was approved as being safe and effective for use as an anti-gas and antiflatulent by the FDA in approximately 1974. Since then, it has been widely used in a variety of pharmaceutical formulations as an anti-gas or antiflatulent agent.
In addition to being available as a liquid, simethicone has been available in powder form since approximately 1990. To create a powder, the simethicone is absorbed into maltodextrin particles, preferably agglomerated maltodextrin. (See U.S. Pat. No. 5,073,384). This so-called “granular simethicone” is especially recommended for use in tablet or other solid dosage formulations containing simethicone.
However, even powdered or granular simethicone tends to be somewhat oily to the touch, and not truly freeflowing. This causes difficulties in producing tablets or other solid dosage compositions containing simethicone.
To overcome this residual oiliness, the manufacturer of granular simethicone recommends compounding it with tribasic calcium phosphate, a well known filler/binder in directly compressible tablets. However, a known drawback of tribasic calcium phosphate is its high tendency to adhere to dies and punches. This is usually overcome by employing higher concentrations of lubricant or anti-adherent in the composition.
We have found it very difficult to compound a tablet using granular simethicone, tribasic calcium phosphate and lubricant. Tablets simply cannot be pressed fast enough. At relatively low speeds, tablets can be readily made without sticking to dies and punches. However at higher speeds, die and punch sticking becomes noticeable to an unacceptable degree. Portions of tablets will stick to the dies and punches of tablet compressing machines. During compression, the punch squeezes simethicone from the solid material. While tablets can be pressed generally successfully at slower speeds, this is not true at production speeds. On a production press (2000-3000 tablets per minute), portions of the tablet will stick to portions of the machine resulting in an end product that is inconsistent and unacceptable.